From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1666) id 2131E3858D32; Mon, 18 Sep 2023 08:56:45 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 2131E3858D32 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1695027405; bh=xWW0SpiKvKRRCcE9+UNwS93K1d93ChGky0L+TPaYGeQ=; h=From:To:Subject:Date:From; b=td0AcIgUuNuIHiAjq97vkbo6Sn0nRu/P5wNDK9ovDfk8QntYFJZGpa7hhNJFvFTQr Sq3O1Q5Y3vf90AfLiYRVBxQgsEM8PduXelNO7gP3zJiJ+B3cCIqAoPylTXhgObcBd/ u41zNrMsxDcymKHOa378akNL3rM5WFUF5ljtU2k8= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Richard Biener To: gcc-cvs@gcc.gnu.org Subject: [gcc r14-4089] tree-optimization/111294 - backwards threader PHI costing X-Act-Checkin: gcc X-Git-Author: Richard Biener X-Git-Refname: refs/heads/master X-Git-Oldrev: 1f9bf6f372da48c75d42f2669ba92f3fd4370fda X-Git-Newrev: d45ddc2c04e471d0dcee016b6edacc00b8341b16 Message-Id: <20230918085645.2131E3858D32@sourceware.org> Date: Mon, 18 Sep 2023 08:56:45 +0000 (GMT) List-Id: https://gcc.gnu.org/g:d45ddc2c04e471d0dcee016b6edacc00b8341b16 commit r14-4089-gd45ddc2c04e471d0dcee016b6edacc00b8341b16 Author: Richard Biener Date: Thu Sep 14 13:06:51 2023 +0200 tree-optimization/111294 - backwards threader PHI costing This revives an earlier patch since the problematic code applying extra costs to PHIs in copied blocks we couldn't make any sense of prevents a required threading in this case. Instead of coming up with an artificial other costing the following simply removes the bits. As with all threading changes this requires a plethora of testsuite adjustments, but only the last three are unfortunate as is the libgomp team.c adjustment which is required to avoid a bogus -Werror diagnostic during bootstrap. PR tree-optimization/111294 gcc/ * tree-ssa-threadbackward.cc (back_threader_profitability::m_name): Remove (back_threader::find_paths_to_names): Adjust. (back_threader::maybe_thread_block): Likewise. (back_threader_profitability::possibly_profitable_path_p): Remove code applying extra costs to copies PHIs. libgomp/ * team.c (gomp_team_start): Assert alloca size to avoid false positive alloc-size diagnostic. gcc/testsuite/ * gcc.dg/tree-ssa/pr111294.c: New test. * gcc.dg/tree-ssa/phi_on_compare-4.c: Adjust. * gcc.dg/tree-ssa/pr59597.c: Likewise. * gcc.dg/tree-ssa/pr61839_2.c: Likewise. * gcc.dg/tree-ssa/ssa-sink-18.c: Likewise. * g++.dg/warn/Wstringop-overflow-4.C: XFAIL subtest on ilp32. * gcc.dg/uninit-pred-9_b.c: XFAIL subtest everywhere. * gcc.dg/vect/vect-117.c: Make scan for not Invalid sum conditional on lp64. Diff: --- gcc/testsuite/g++.dg/warn/Wstringop-overflow-4.C | 4 +- gcc/testsuite/gcc.dg/tree-ssa/phi_on_compare-4.c | 4 +- gcc/testsuite/gcc.dg/tree-ssa/pr111294.c | 32 +++++++++++++ gcc/testsuite/gcc.dg/tree-ssa/pr59597.c | 8 +--- gcc/testsuite/gcc.dg/tree-ssa/pr61839_2.c | 4 +- gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-18.c | 6 ++- gcc/testsuite/gcc.dg/uninit-pred-9_b.c | 2 +- gcc/testsuite/gcc.dg/vect/vect-117.c | 2 +- gcc/tree-ssa-threadbackward.cc | 60 +++--------------------- libgomp/team.c | 2 + 10 files changed, 56 insertions(+), 68 deletions(-) diff --git a/gcc/testsuite/g++.dg/warn/Wstringop-overflow-4.C b/gcc/testsuite/g++.dg/warn/Wstringop-overflow-4.C index faad5bed074..275ecac01b5 100644 --- a/gcc/testsuite/g++.dg/warn/Wstringop-overflow-4.C +++ b/gcc/testsuite/g++.dg/warn/Wstringop-overflow-4.C @@ -151,7 +151,9 @@ void test_strcpy_new_int16_t (size_t n, const size_t vals[]) as size_t as a result of threading. See PR 101688 comment #2. */ T (S (1), new int16_t[r_0_imax]); - T (S (2), new int16_t[r_0_imax + 1]); + /* Similar to PR 101688 the following can result in a bougs warning because + of threading. */ + T (S (2), new int16_t[r_0_imax + 1]); // { dg-bogus "into a region of size" "" { xfail { ilp32 } } } T (S (9), new int16_t[r_0_imax * 2 + 1]); int r_1_imax = SR (1, INT_MAX); diff --git a/gcc/testsuite/gcc.dg/tree-ssa/phi_on_compare-4.c b/gcc/testsuite/gcc.dg/tree-ssa/phi_on_compare-4.c index 1e09f89af9f..6240d1cdd6d 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/phi_on_compare-4.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/phi_on_compare-4.c @@ -1,5 +1,5 @@ /* { dg-do compile } */ -/* { dg-options "-Ofast -fdump-tree-dom2" } */ +/* { dg-options "-Ofast -fdump-tree-threadfull1-stats" } */ void g (int); void g1 (int); @@ -37,4 +37,4 @@ f (long a, long b, long c, long d, int x) g (c + d); } -/* { dg-final { scan-tree-dump-times "Removing basic block" 1 "dom2" } } */ +/* { dg-final { scan-tree-dump "Jumps threaded: 2" "threadfull1" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr111294.c b/gcc/testsuite/gcc.dg/tree-ssa/pr111294.c new file mode 100644 index 00000000000..9ad912bad0b --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr111294.c @@ -0,0 +1,32 @@ +/* { dg-do compile } */ +/* { dg-options "-Os -fdump-tree-optimized" } */ + +void foo(void); +static short a; +static int b, c, d; +static int *e, *f = &d; +static int **g = &e; +static unsigned char h; +static short(i)(short j, int k) { return j > k ?: j; } +static char l() { + if (a) return b; + return c; +} +int main() { + b = 0; + for (; b < 5; ++b) + ; + h = l(); + if (a ^ 3 >= i(h, 11)) + a = 0; + else { + *g = f; + if (e == &d & b) { + __builtin_unreachable(); + } else + foo(); + ; + } +} + +/* { dg-final { scan-tree-dump-not "foo" "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr59597.c b/gcc/testsuite/gcc.dg/tree-ssa/pr59597.c index 0f66aae87bb..26c81d9dbb7 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/pr59597.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr59597.c @@ -1,5 +1,5 @@ /* { dg-do compile } */ -/* { dg-options "-Ofast -fdisable-tree-cunrolli -fdump-tree-threadfull1-details" } */ +/* { dg-options "-Ofast -fdump-tree-ethread-details" } */ typedef unsigned short u16; typedef unsigned char u8; @@ -56,8 +56,4 @@ main (int argc, char argv[]) return crc; } -/* We used to have no threads in vrp-thread1 because all the attempted - ones would cross loops. Now we get 30+ threads before VRP because - of loop unrolling. A better option is to disable unrolling and - test for the original 4 threads that this test was testing. */ -/* { dg-final { scan-tree-dump-times "Registering jump thread" 4 "threadfull1" } } */ +/* { dg-final { scan-tree-dump-times "Registering jump thread" 2 "ethread" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr61839_2.c b/gcc/testsuite/gcc.dg/tree-ssa/pr61839_2.c index 0e0f4c02113..a78e444038a 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/pr61839_2.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr61839_2.c @@ -1,6 +1,8 @@ /* PR tree-optimization/61839. */ /* { dg-do compile } */ -/* { dg-options "-O2 -fdump-tree-evrp" } */ +/* Disable jump threading, we want to avoid separating the division/modulo + by zero paths - we'd isolate those only later. */ +/* { dg-options "-O2 -fno-thread-jumps -fdump-tree-evrp" } */ /* { dg-require-effective-target int32plus } */ __attribute__ ((noinline)) diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-18.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-18.c index fd6c8677212..13b9ba4f70f 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-18.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-18.c @@ -198,7 +198,9 @@ compute_on_bytes (uint8_t *in_data, int in_len, uint8_t *out_data, int out_len) exits after gimple loop optimizations, which generates instructions executed each iteration in loop, but the results are used outside of loop: With -m64, - "Sinking _367 = (uint8_t *) _320; + "Sinking op_230 = op_244 + 2; + from bb 63 to bb 94 + Sinking _367 = (uint8_t *) _320; from bb 31 to bb 90 Sinking _320 = _321 + ivtmp.25_326; from bb 31 to bb 90 @@ -213,4 +215,4 @@ compute_on_bytes (uint8_t *in_data, int in_len, uint8_t *out_data, int out_len) base+index addressing modes, so the ip[len] address computation can't be made from the IV computation above. */ - /* { dg-final { scan-tree-dump-times "Sunk statements: 4" 1 "sink2" { target lp64 xfail { riscv64-*-* } } } } */ + /* { dg-final { scan-tree-dump-times "Sunk statements: 5" 1 "sink2" { target lp64 xfail { riscv64-*-* } } } } */ diff --git a/gcc/testsuite/gcc.dg/uninit-pred-9_b.c b/gcc/testsuite/gcc.dg/uninit-pred-9_b.c index 0f508fa56e1..3c83d505ec0 100644 --- a/gcc/testsuite/gcc.dg/uninit-pred-9_b.c +++ b/gcc/testsuite/gcc.dg/uninit-pred-9_b.c @@ -17,7 +17,7 @@ int foo (int n, int l, int m, int r) if (l > 100) if ( (n <= 9) && (m < 100) && (r < 19) ) - blah(v); /* { dg-bogus "uninitialized" "bogus warning" { xfail powerpc*-*-* cris-*-* riscv*-*-* } } */ + blah(v); /* { dg-bogus "uninitialized" "bogus warning" { xfail *-*-* } } */ if ( (n <= 8) && (m < 99) && (r < 19) ) blah(v); /* { dg-bogus "uninitialized" "pr101674" { xfail mmix-*-* } } */ diff --git a/gcc/testsuite/gcc.dg/vect/vect-117.c b/gcc/testsuite/gcc.dg/vect/vect-117.c index 010d63c9ad8..4755e39f951 100644 --- a/gcc/testsuite/gcc.dg/vect/vect-117.c +++ b/gcc/testsuite/gcc.dg/vect/vect-117.c @@ -61,4 +61,4 @@ int main (void) /* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */ /* { dg-final { scan-tree-dump-times "possible dependence between data-refs" 0 "vect" } } */ -/* { dg-final { scan-tree-dump-not "Invalid sum" "optimized" } } */ +/* { dg-final { scan-tree-dump-not "Invalid sum" "optimized" { target { lp64 } } } } */ diff --git a/gcc/tree-ssa-threadbackward.cc b/gcc/tree-ssa-threadbackward.cc index d5da4b0c1b1..c45f4b261ad 100644 --- a/gcc/tree-ssa-threadbackward.cc +++ b/gcc/tree-ssa-threadbackward.cc @@ -62,7 +62,7 @@ class back_threader_profitability { public: back_threader_profitability (bool speed_p, gimple *stmt); - bool possibly_profitable_path_p (const vec &, tree, bool *); + bool possibly_profitable_path_p (const vec &, bool *); bool profitable_path_p (const vec &, edge taken, bool *irreducible_loop); private: @@ -126,9 +126,6 @@ private: auto_bitmap m_imports; // The last statement in the path. gimple *m_last_stmt; - // This is a bit of a wart. It's used to pass the LHS SSA name to - // the profitability engine. - tree m_name; // Marker to differentiate unreachable edges. static const edge UNREACHABLE_EDGE; // Set to TRUE if unknown SSA names along a path should be resolved @@ -366,7 +363,7 @@ back_threader::find_paths_to_names (basic_block bb, bitmap interesting, // on the way to the backedge could be worthwhile. bool large_non_fsm; if (m_path.length () > 1 - && (!profit.possibly_profitable_path_p (m_path, m_name, &large_non_fsm) + && (!profit.possibly_profitable_path_p (m_path, &large_non_fsm) || (!large_non_fsm && maybe_register_path (profit)))) ; @@ -517,23 +514,19 @@ back_threader::maybe_thread_block (basic_block bb) return; enum gimple_code code = gimple_code (stmt); - tree name; - if (code == GIMPLE_SWITCH) - name = gimple_switch_index (as_a (stmt)); - else if (code == GIMPLE_COND) - name = gimple_cond_lhs (stmt); - else + if (code != GIMPLE_SWITCH + && code != GIMPLE_COND) return; m_last_stmt = stmt; m_visited_bbs.empty (); m_path.truncate (0); - m_name = name; // We compute imports of the path during discovery starting // just with names used in the conditional. bitmap_clear (m_imports); ssa_op_iter iter; + tree name; FOR_EACH_SSA_TREE_OPERAND (name, stmt, iter, SSA_OP_USE) { if (!gimple_range_ssa_p (name)) @@ -588,15 +581,12 @@ back_threader::debug () *LARGE_NON_FSM whether the thread is too large for a non-FSM thread but would be OK if we extend the path to cover the loop backedge. - NAME is the SSA_NAME of the variable we found to have a constant - value on PATH. If unknown, SSA_NAME is NULL. - ?? It seems we should be able to loosen some of the restrictions in this function after loop optimizations have run. */ bool back_threader_profitability::possibly_profitable_path_p - (const vec &m_path, tree name, + (const vec &m_path, bool *large_non_fsm) { gcc_checking_assert (!m_path.is_empty ()); @@ -645,44 +635,6 @@ back_threader_profitability::possibly_profitable_path_p if (j < m_path.length () - 1) { int orig_n_insns = m_n_insns; - /* PHIs in the path will create degenerate PHIS in the - copied path which will then get propagated away, so - looking at just the duplicate path the PHIs would - seem unimportant. - - But those PHIs, because they're assignments to objects - typically with lives that exist outside the thread path, - will tend to generate PHIs (or at least new PHI arguments) - at points where we leave the thread path and rejoin - the original blocks. So we do want to account for them. - - We ignore virtual PHIs. We also ignore cases where BB - has a single incoming edge. That's the most common - degenerate PHI we'll see here. Finally we ignore PHIs - that are associated with the value we're tracking as - that object likely dies. */ - if (EDGE_COUNT (bb->succs) > 1 && EDGE_COUNT (bb->preds) > 1) - { - for (gphi_iterator gsip = gsi_start_phis (bb); - !gsi_end_p (gsip); - gsi_next (&gsip)) - { - gphi *phi = gsip.phi (); - tree dst = gimple_phi_result (phi); - - /* Note that if both NAME and DST are anonymous - SSA_NAMEs, then we do not have enough information - to consider them associated. */ - if (dst != name - && name - && TREE_CODE (name) == SSA_NAME - && (SSA_NAME_VAR (dst) != SSA_NAME_VAR (name) - || !SSA_NAME_VAR (dst)) - && !virtual_operand_p (dst)) - ++m_n_insns; - } - } - if (!m_contains_hot_bb && m_speed_p) m_contains_hot_bb |= optimize_bb_for_speed_p (bb); for (gsi = gsi_after_labels (bb); diff --git a/libgomp/team.c b/libgomp/team.c index 54dfca8080a..b4fd6f2704c 100644 --- a/libgomp/team.c +++ b/libgomp/team.c @@ -756,6 +756,8 @@ gomp_team_start (void (*fn) (void *), void *data, unsigned nthreads, attr = &thread_attr; } + if (i >= nthreads) + __builtin_unreachable (); start_data = gomp_alloca (sizeof (struct gomp_thread_start_data) * (nthreads - i));